On March 7, the two most rapidly ascendant militant Islamic groups joined forces, in words at least, as Nigeria’s Boko Haram declared its allegiance to the Islamic State group in Iraq and Syria.

The rise of these two groups has left al-Qaida aligned al-Shabab in the dust, damaging its capacity to attract foreign recruits, said Ken Menkhaus, a Somalia expert and professor at Davidson College, North Carolina.

“Al-Shabab is really overshadowed by IS,” said Menkhaus.

Al-Shabab aligned with al-Qaida in 2012, but a turn to the Islamic State group now seems possible. “Al-Shabab has renewed its links with al-Qaida but hasn’t yet said anything negative about IS,” said Matt Bryden, director of Sahan Research in Nairobi. “There’s certainly interest in parts of al-Shabab to align with IS.”

Al-Shabab websites and radio stations enthusiastically cover Islamic State news and offer positive commentary, including of Boko Haram-Islamic State group union, announced earlier this month.

Al-Shabab’s internal debate over whether to shift allegiance to the Islamic State franchise intensified with the death of the group’s leader and al-Qaida stalwart, Ahmed Abdi Godane, in a U.S. missile strike last year.

New emir Ahmed Umar is an al-Qaida loyalist while other senior figures — among them Mahad Karate who runs the Amniyat, a special internal security wing that deals in intelligence and assassinations — advocate for a switch to the ascendant Islamic State group, experts say.

Al-Shabab has fallen a long way from its height just a few years ago when it was the extremist group of choice for aspiring jihadis worldwide.

Mohammed Emwazi, recently revealed as Islamic State executioner “Jihadi John,” is accused by British authorities of attempting to travel to Somalia via Tanzania in August 2009. Michael Adebolajo, the killer of an off-duty British soldier in London in May 2013, is similarly accused of attempting to join al-Shabab, via Kenya, in November 2010.

Scores of non-Somalis and diaspora Somalis once bolstered the ranks of al-Shabab, but now the group struggles to attract recruits from outside East Africa, even among its own nationals.

“Somalis in the diaspora are heading to Iraq and Syria, not Somalia,” said Bryden.

Last year it emerged that Sayid Hussein Feisal Ali, the Finland-born son of a presidential aspirant in Somaliland, had traveled to Syria to join the Islamic State group.

The FBI believes there are many more.

Last month Hamza Naj Ahmed, from Minnesota, was charged with “conspiring to provide material support” to the Islamic State group.

“Hamza Ahmed is at least the fourth person from the Twin Cities charged as a result of an ongoing investigation into individuals who have traveled or are attempting to travel to Syria in order to join a foreign terrorist organization,” said U.S. attorney Andrew Luger.

Local media in Minnesota reported that up to 15 young Somali-Americans had traveled to Syria by the middle of last year, and that some had been killed fighting with the Islamic State group.

Al-Shabab’s allure for foreign jihadis had waned even before the Islamic State group seized territory, and the world’s attention, last summer.

Its most notorious foreign recruit was Alabama-born U.S. citizen Omar Hammami, known as Abu al-Amriki, who appeared in recruitment videos praising the joys of jihad and rapping, badly.

But Hammami fell victim to an internal purge in 2013 that killed or alienated many of the group’s foreign fighters.

In two recent propaganda videos al-Shabab has sought to regain some ground lost on the media battlefield, recounting attacks in Kenya that targeted Nairobi’s Westgate shopping mall in 2013 and the coastal town of Mpeketoni in 2014.

But unlike the slick, punchy, international propaganda put out by the Islamic State group in videotaped executions or drone-shot footage of war zones, al-Shabab productions are flabby and parochial. The Westgate video ran to one hour and sixteen minutes and provided no new insight.

“I was unimpressed,” said Menkhaus. “They need a good jihadi editor.”

The film ended with a call for Muslims in the U.S., Britain and France to launch copycat attacks on shopping malls near them, which only underlined al-Shabab’s own inability to mount such assaults.

The Mpeketoni video reveled in slow-motion executions of civilians by masked gunmen. But by taking an attack on a small town in Kenya as its subject matter, the film only had appeal for a regional audience — reflecting al-Shabab’s current profile of mostly local recruits from Kenya and Somalia, the two countries where its energies are currently focused.

Al-Shabab is “stronger regionally, but weaker globally,” said Menkhaus. However, he warned that while the militants are down, they are not yet out. “Al-Shabab has had its day before and come back,” he said.